A replica of dinosaur eggs hatching on its nest.
There have been a lot of studies that suggest that dinosaurs are classified as "somewhere in between" as warm-blooded and cold-blooded.
"Dinosaurs sit at an evolutionary point between birds, which are warm-blooded, and reptiles, which are cold-blooded. Our results suggest that all major groups of dinosaurs had warmer body temperatures than their environment," said by Robin Dawson, who conducted the study while still a doctoral student in geology and geophysics at Yale.
Dawson, together with Yale Paleontologist Pincelli Hull a co-author of the study, and former Yale researchers Daniel Field and Hagit Affek, used the clumped isotope paleothermometry in determining the ordering of oxygen and carbon atoms to calculate the mother's internal temperature and come up with their findings.
Taking a sample from three major dinosaur groups, Dawson and her team tested several fossil eggshells from those closely related to birds and the distantly related to birds, including eggshells from the Troodon a carnivore, Maiasaura an herbivore, and Megaloolithus a massive dinosaur.
The eggshells from Troodon, a small, meat-eating theropod were tested 100.4, 80.6, and 82.4 degrees Fahrenheit (38 degrees, 27 degrees and 28 degrees Celsius). While the eggshells from the duck-billed dinosaur Maiasaura yielded a temperature of 111.2 degrees Fahrenheit (44 degrees Celsius). Both of the samples came from Alberta, Canada. Megaloolithus, on the other hand, tested at 96.8 degrees Fahrenheit (36 degrees Celsius) which eggshell fossils came from Romania.
To determine the temperature of the local environment and to test whether it is higher or lower than the dinosaurs, in the same location where they found the eggshell fossils the researchers conducted the same testing method to the cold-blooded vertebrates.The Troodon were found to be 18 degrees Fahrenheit (10 degrees Celsius) warmer than their environment, while the Maiasaura is 27 degrees Fahrenheit (15 degrees Celsius) warmer and the Megaloolithus is 5.4-10.8 degrees Fahrenheit (3-6 degrees Celsius).
"What we found indicates that the ability to metabolically raise their temperatures above the environment was an early, evolved trait for dinosaurs," Dawson added.
This may imply that the dinosaur's size and growth is not necessarily a good indicator of their body temperature. Additionally, with the ongoing discussion on the feathers of the birds, this could also help explain its significance.
"It's possible that dense feathers were primarily selected for insulation, as body size decreased in theropod dinosaurs on the evolutionary pathway to modern birds," Dawson explained. "Feathers could have then later been co-opted for sexual display or flying."
New Evidence of the Asteroid That Killed the Dinosaurs
As researchers continue to learn more about the history of dinosaurs, earlier this month a new study suggests that because of this explosion, one form of life thrived - the bacteria. Moreover, a separate study published in October 2019 said that another reason for the dinosaurs to go extinct is when the asteroid acidified the ocean after the impact.
Whether it's because of the asteroids or volcanos, dinosaurs could be the recipients of a geologic one-two punch, with volcanism weakening the ecosystem making it vulnerable to an incoming meteor.
This debate may go on for years as scientists find more clues and develop new techniques in unraveling the past but there is one thing that scientists have just discovered the answer to- that is, dinosaurs are warm-blooded.
